With several years of development, the face recognition has got wide attention, and has made great progress. Nowadays, the face recognition technology has been widely applied in fields such as the national security, the military security, the public security, or the like, and is used, for example, for the smart video monitoring, the smart access control, the custom identification verification, or the like. In recent years, the face recognition is also widely applied in fields such as Internet, finance, or the like, and is used, for example, to open a credit card account or a stock account online, to verify identification, or the like.
Currently, most face recognition methods are based on a face image with a low resolution, and only structure information on the face is used. In the traditional face recognition, generally, an image with a low resolution (generally, the distance between both eyes of the face being larger than 30 pixels) is sufficient for the recognition. In this way, only global structure information on the face may be obtained, and most detail features of the face are lost, resulting in a relatively low accuracy of the face recognition.